Flame-retardant, high temperature resistant thermosets on the basis of naphthalene-based epoxy resins and cyanate esters

ABSTRACT

The embodiments relate to a polymerisable thermoset composition having improved flame retardant properties, a polymerised thermoset having improved flame retardant properties, a process for manufacturing the polymerised thermoset, and use of the polymerisable thermoset composition to produce lightweight construction components, preferably carbon fibre composites (CFRP), and a lightweight construction component, preferably carbon fibre composite (CFRP), containing the polymerised thermoset.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to European Patent Application No. 15001 936.2, filed Jun. 30, 2015, and to U.S. patent application Ser. No.15/198,831, filed Jun. 30, 2016, each of which is incorporated herein byreference in its entirety

TECHNICAL FIELD

The embodiments described herein relate to a polymerisable thermosetcomposition having improved flame retardant properties, a polymerisedthermoset having improved flame retardant properties, a process formanufacturing the polymerised thermoset, and the use of thepolymerisable thermoset composition to produce lightweight constructioncomponents, preferably carbon fibre composites (CFRP), and a lightweightconstruction component, preferably carbon fibre composite (CFRP),containing the polymerised thermoset.

BACKGROUND

Today's thermoset material systems used in commercial applications havevery limited thermal resistance, and are manufactured on the basis ofepoxy resins. However, this limited thermal stability is too low formany applications, particularly for environments in which increasedthermal and mechanical loads occur. On the other hand, othercommercially available materials for high-temperature applications, suchas BMI or polyimide resins, are either toxic or extremely expensive andtherefore not suitable for commercial use. Cyanate esters have anextremely high glass transition temperature of up to 400° C. This is dueto the high crosslinking density of the thermoset network which howeveralso means that the material is very brittle. Because of its brittlenessuntil now this type of thermoset system has not found any commercial usein aviation. Moreover, most cyanate ester systems require a curingtemperature higher than 200° C., which further affects the financialviability of said systems. Additionally, most of the curing agents usedare harmful to health.

The materials should also exhibit good flame retardant properties. Theflame retardants used should also not be associated with any toxiceffects, and should not impair the physical properties of the materials,such as the glass transition temperature and mechanical properties. Theflame retardants should also have the lowest possible migrationtendency, and small quantities of the flame retardant should besufficient to achieve the desired flame resistance. Many cyanate ester(CE)/epoxy combinations are already known.

For example, U.S. Pat. No. 5,494,981; US 2012/0309923; JP2009013205 (A);and C.-S. Wang, M. C. Lee: Synthesis, characterisation and properties ofmultifunctional naphthalene containing epoxy resins cured with cyanateester, Journal of applied polymer science 73 (1999) 1611-1622, describeCE/epoxy mixtures that are produced with the aid of various curingagents, and catalysts respectively. These make use primarily ofnonylphenol/transition metal catalysts as well as Brønstedt acids andamines. Transition metal catalysts are usually not soluble in the resinmatrix, so phenols, such as nonylphenol are used as co-catalysts. Notonly that there are health concerns surrounding the transition metalcatalysts used, nonylphenol has been cited as a “substance of very highconcern” (SVHC) since December 2012 by REACH [European Chemical Agency,Support document for identification of 4-Nonylphenol branched andlinear, 13 Dec. 2012]. Additionally a significant disadvantage ofBrønstedt-acids is that most of them are prepared on an aqueous basis.Since cyanate esters tend to form carbamates in the presence of water,which degrade into CO₂ and amines at elevated temperatures, therebyimpairing the performance of the materials, these catalysts should notbe used.

Moreover, JP 08-176274 (A); JP 2010-059363; C.-S. Wang, M. C. Lee:Synthesis, characterisation and properties of multifunctionalnaphthalene-containing epoxy resins cured with cyanate ester, Journal ofapplied polymer science 73 (1999) 1611-1622, for example, describematerials prepared from cyanate esters and naphthalene-based epoxies.The naphthalene-based epoxies used in JP 08-176274 (A) are low-molecularand difunctional, which means that a naphthalene molecule has at mosttwo glycidyl ether functionalities.

Because the naphthalene has such a low functionality, its crosslinkingdensity is also low compared with more highly functionalised epoxies. Inturn, low crosslinking density is also associated with lower thermalstability (Tg) and higher water absorption, but also reducedbrittleness.

The epoxies used in JP 2010-059363 for preparing CE/epoxy materials areprepolymers based on polyphenylene with a naphthalene-functionality inthe polymer backbone. These prepolymers only have one glycidyl etherfunctionality per repeating unit, which again results in a lowcrosslinking density. Moreover, unlike a backbone consisting only ofnaphthalene, the introduction of the polyphenylene ether group has theeffect of increasing the molecular mobility of the polymer backbone.This might improve the mechanical properties of the material, but itwould also lead to a decrease of the thermal properties (Tg). In Wanget. al., low-molecular, tetrafunctional naphthalene-based epoxies areused in CE/epoxy mixtures.

The advantage of these tetraglycidyl ether naphthalenes is that theresulting thermoset network exhibits enormously high crosslinkingdensity and the associated good thermal as well as hygrothermalproperties. In this way, it is possible to avoid lowering the Tg too farby mixing the epoxy into the cyanate ester. The curing process in thispublication was carried out using nonylphenol/copper(II)acetylacetonate, which is to be avoided at all costs for the reasons givenabove. The flame resistance of these systems can also be improvedfurther.

Flame retardants can be added to polymers generally as simple additives(additive flame protection), or they may be copolymerised into thepolymer matrix using specially functionalised monomers. However, ifspecially functionalised monomers are used, other properties of theresin matrix may be affected negatively. In the case of additive flameprotection, the flame retardants used may tend to migrate more readily,since flame retardants used are not bonded to the polymer matrix.

Since cyanate esters already possess a high flame resistance because oftheir high aromatic content, the known literature contains only fewexamples in which cyanate esters have been chemically modified withflame retardants.

However, the resin matrix was chemically modified with the flameretardants before the curing process for this purpose. Such concepts aredescribed for example in C. H. Lin, Polymer 2004, 45, 7911-7926; T.-H.Ho, H.-J. Hwang, J.-Y. Shieh, M.-C. Chung, Reactive and FunctionalPolymers 2009, 69, 176-182 and C. H. Lin, K. Z. Yang, T. S. Leu, C. H.Lin, J. W. Sie, Journal of Polymer Science Part A: Polymer Chemistry2006, 44, 3487-3502.

Even if the physical and thermal properties of the polymer systems arenot compromised thereby, further process steps are still necessary inorder to modify the respective components. Furthermore, depending on therequirements profile the polymer must fulfil, it may also be necessaryto use starter materials that have been modified differently, whichrenders their production more complicated and thus also more expensive.

Therefore, it would be desirable to provide a polymerisable thermosetcomposition that is resistant to high temperatures and has good flameretardant qualities. It should also be curable at moderate temperaturesand should not contain any water-based compounds such as Brønstedt acidsor curing agents or catalysts that are harmful to health, such astransition metal catalysts, and it should be modifiable in terms ofimpact resistance. It is further desirable to produce a polymerisablethermoset composition that is suitable for manufacturing lightweightconstruction components such as carbon fibre composites (CFRP).

Given the above, an embodiment provides a highly flame retardant,polymerisable thermoset composition, which additionally is resistant tohigh temperatures in the cured state, and particularly has increasedthermal resistance, compared to pure epoxy resins. A furthercharacteristic of the present embodiment is that in the cured state ofthe polymerisable thermoset composition, the flame retardant containedtherein exhibits a low tendency to migrate.

Another characteristic of the present embodiment is that thepolymerisable thermoset composition should not require a resin matrixthat has been modified with flame protection agents before the curingprocess.

In accordance with certain embodiments, in the cured state thepolymerisable thermoset composition has a high glass transitiontemperature, particularly a glass transition temperature, that is higherthan those of the previously known CE/epoxy combinations. Still anothercharacteristic of the present embodiment is that the polymerisablethermoset composition should have high impact resistance in the currentstate, particularly an impact resistance that is improved compared withpure CE/epoxy combinations. Another characteristic of the presentembodiment is that the polymerisable thermoset composition should becurable at moderate temperatures, and in particular should have a lowercuring temperature than pure cyanate esters. A further characteristic ofthe present embodiment is that the polymerisable thermoset compositionshould exhibit better resistance to hydrolysis than pure cyanate esters.Still another characteristic of the present embodiment is that thepolymerisable thermoset composition should not contain any curing agentsand/or catalysts that are injurious to health.

These and other features and characteristics are provided by thesubject-matter defined in the claims. Advantageous embodimentsconstitute the subject matter of dependent claims.

SUMMARY

Accordingly, a present embodiment is a polymerisable thermosetcomposition comprising: a) a di- or polyfunctional organic cyanate esterresin, b) a naphthalene based epoxy resin, and c1) at least onephosphorus-containing phenol and/or c2) at least onephosphorus-containing epoxy and at least one diamine.

In the cured state, the polymerisable thermoset composition according tothe embodiment is resistant to high temperatures and has increasedthermal resistance and flame resistance particularly compared with pureepoxy resins. A further advantage is that the polymerisable thermosetcompound according to the embodiment does not require modifications tobe made to components a) and b) to provide flame protection therefor,since the flame protection agent is already contained in the curingagent component. A further advantage is that in the cured state theflame protection agents in the polymerisable thermoset compositionaccording to the embodiment do not have any tendency to migrate, andunlike halogen-containing flame protection agents, decompositionproducts that are poisonous and harmful to health can be avoided.

A further advantage is that in the cured state the polymerisablethermoset composition according to the invention has a high glasstransition temperature, which is in particular higher than previouslyknown CE/epoxy combinations. A further advantage is that in the curedstate the polymerisable thermoset composition according to theembodiment is highly impact resistant, and the impact resistance thereofis in particular improved compared with pure CE/epoxy combinations. Afurther advantage is that polymerisable thermoset composition accordingto the embodiment can be cured at a moderate temperature, which is inparticular lower than for pure cyanate esters. A further advantage isthat the polymerisable thermoset composition according to the embodimenthas improved resistance to hydrolysis compared with pure cyanate esters.A further advantage is that the polymerisable thermoset compositionaccording to the embodiment contains no curing agents and/or catalyststhat are harmful to health.

The di- or polyfunctional organic cyanate ester resin and thenaphthalene-based epoxy resin typically contain no phosphorus.

For example, the phosphorus-containing phenol is a(hydrocarbyl-)-phosphonic acid ester and/or contains9-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as a structural unit.

For example, the phosphorus-containing phenol contains one of thefollowing structural units (I) and (II) wherein

-   -   n is a number between 1 and 1000, preferably between 200 and        500,    -   o is a number between 0 and 4, preferably between 0 and 2, more        preferably 0 or 1, and is most preferably 0,    -   p is a number between 0 and 4, preferably between 0 and 2, more        preferably 0 or 1, and is most preferably 0,    -   r is a number between 0 and 3, preferably between 0 and 2, more        preferably 0 or 1, and is most preferably 0,    -   R¹ is a C₁-C₁₀ alkyl,    -   R² is a C₁-C₁₀ alkyl, and    -   R³ is a C₁-C₁₀ alkyl    -   or

-   -   s is a number between 1 and 1000, preferably between 100 and        600,    -   t is a number between 0 and 4, preferably between 0 and 2, more        preferably 0 or 1 and most preferably is 0, and    -   R⁴ is a C₁-C₁₀ alkyl

The following compounds are examples of phosphorus-containing phenols

wherein n is a number between 200 and 500 or

wherein s is a number between 100 and 600.

The formation of triazines based on cyanate esters is catalysed by thefree hydroxyl functionalities, which optimises the curing process interms of duration and the degree of hardening. Moreover, the compoundsare not harmful to health, and because of their high phosphorus contentthey lend good flame resistance to the cured polymer mixture.

For example, the phosphorus-containing epoxy is a(hydrocarbyl-)-phosphonic acid ester and/or contains9-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as the structural unit.The phosphorus-containing epoxy preferably contains9-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as the structural unit.

For example, the phosphorus-containing epoxy contains the followingstructural unit (III) wherein:

-   -   a is a number between 0 and 4, preferably between 0 and 2, more        preferably 0 or 1 and most preferably is 0    -   b is a number between 0 and 4, preferably between 0 and 2, more        preferably 0 or 1 and most preferably is 0,    -   c is a number between 0 and 3, preferably between 0 and 2, more        preferably 0 or 1 and most preferably is 0,    -   d is a number between 0 and 3, preferably between 0 and 2, more        preferably 0 or 1 and most preferably is 0,    -   e is a number between 1 and 1000, preferably between 200 and        500,    -   f is a number between 1 and 1000, preferably between 50 and 200,    -   R¹⁰ is a C₁-C₁₀ alkyl,    -   R¹¹ is a C₁-C₁₀ alkyl,    -   R¹² is a C₁-C₁₀ alkyl or hydrogen, preferably methyl or        hydrogen, and most preferably hydrogen,    -   R¹³ is a C₁-C₁₀ alkyl or hydrogen, preferably methyl or        hydrogen, and most preferably hydrogen,    -   R¹⁴ is a C₁-C₁₀ alkyl or hydrogen, preferably methyl or        hydrogen, and most preferably hydrogen,    -   R¹⁵ is a C₁-C₁₀ alkyl or hydrogen, preferably methyl or        hydrogen, and most preferably hydrogen,    -   R¹⁶ is a C₁-C₁₀ alkyl,    -   R¹⁷ is a C₁-C₁₀ alkyl,    -   R¹⁸ is a C₁-C₁₀ alkyl or hydrogen, preferably methyl or        hydrogen, and most preferably hydrogen, and    -   R¹⁹ is a C₁-C₁₀ alkyl or hydrogen, preferably methyl or        hydrogen, and most preferably hydrogen.

The following compound is an example of the phosphorus-containing epoxy:

wherein e is a number between 200 and 500, and

wherein f is a number between 50 and 200.

Such an epoxy represents an additional epoxy in the resin mixture, andconsequently a diamine is also used as a curing agent.

The diamine is typically an aromatic diamine, preferably selected fromthe group comprising 2,4-diaminotoluene, 2,6-diaminotoluene,3,5-diethyl-2,4-diaminotoluene, 3,5-diethyl-2,6-diaminotoluene, andprimary mono-, di-, tri- or tetra-alkyl substituted 4,4′-diaminodiphenylmethanes, 6-methyl-2,4-bis(methylthio)phenylene-1,3-diamine and2-methyl-4,6-bis(methylthio)phenylene-1,3-diamine.

Since components c1) and/or c2) function as curing agents, it is notnecessary to use curing agents and/or catalysts with harmful healtheffects.

The polymerisable thermoset composition according to the embodimenttherefore preferably does not contain any curing agents and/or catalystswith harmful health effects.

If the polymerisable thermoset composition according to the embodimentshould contain diamine, the total quantity of diamine relative to thepolymerisable thermoset composition is 0.25 to 5.0% by weight,preferably 0.1 to 2.0% by weight or 0.2 to 1.5% by weight.Alternatively, if the polymerisable thermoset composition contains thearomatic diamine, the content should be in a quantity of for example 0.4to 1.2% by weight or 0.5 to 1.0% by weight.

In one embodiment, component c2) is present and component c1) is notpresent.

In a further, preferred embodiment, component c1) is present andcomponent c2) is not present. In this embodiment, a diamine is normallynot needed to function as an additional curing agent component. Thepolymerisable thermoset composition of this embodiment preferably doesnot contain a diamine.

The compositions according to the embodiment have significantly improvedflame retardant properties, and compounds containing component c1) havestill better flame retardant properties than the compositions accordingto the embodiment that contain component c2).

The total quantity of components c1) and c2) relative to thepolymerisable thermoset composition is typically in the range from 5.5to 20% by weight, preferably in the range from 6.0 to 15% by weight, andmore preferably in the range from 6.5 to 12% by weight.

The di- or polyfunctional organic cyanate ester resin is for example acyanate having formula (IV):

wherein IV, R² and R³ independently of one another are hydrogen orC₁-C₁₀ alkyl, and n represents a whole number from 0 to 20.

The di- or polyfunctional organic cyanate ester resin is for example acyanate having formula (IV):

wherein R¹, R² and R³ are hydrogen, and n represents an integer from 0to 20.

For example, the naphthalene-based epoxy resin represents a polymericnaphthalene-based epoxy resin.

For example, the naphthalene-based epoxy resin is a naphthalene-basedepoxy having formula (V):

wherein n represents a whole number from 1 to 50.

For example, the polymerisable thermoset composition contains the di- orpolyfunctional organic cyanate ester resin and the naphthalene-basedepoxy resin in a weight ratio (weight/weight) from 10:1 to 1:1.

For example, the polymerisable thermoset composition comprises at leastone high-performance thermoplast, also called an impact modifier,preferably at least one high-performance thermoplast selected from thegroup comprising polysulfones (PSU), for example polyethersulfone (PES)and polyphenylsulfone (PPSU), polyetherimide (PEI), polysulfone (PSU),polycarbonate (PC), silicone rubber and mixtures thereof.

The impact modifier may also be present in the form of core-shellparticles, preferably containing at least one high-performancethermoplast, typically as the core.

The shell of the core-shell particles typically consists of a polymermatrix containing an epoxy resin, for example, and a cyanate ester ormixtures thereof. The core contains, preferably consists of, a differentpolymer, selected for example from the group comprising silicone rubber,nitrile rubber, styrene-butadiene rubber, polyisoprene rubber,polybutadiene, butyl rubber, fluoroelastomers, etc., and mixturesthereof, made from silicone rubber for example.

The polymerisable thermoset composition contains for example the di- orpolyfunctional organic cyanate ester resin and the at least onehigh-performance thermoplast in a weight ratio (weight/weight) from100:1 to 6:1 and/or the polymerisable thermoset composition contains thenaphthalene-based epoxy resin and the at least one high-performancethermoplast in a weight ratio (weight/weight) from 50:1 to 3:1. In thecase of core-shell particles, the weight specification refers to thetotal mass of the core-shell particle.

The present embodiment further provides a polymerised thermoset thatrepresents a product of reaction of the polymerisable thermosetcomposition, as described in this document.

The polymerised thermoset has a glass transition temperature from 280°C. to 300° C., for example.

The present embodiment further provides a process for manufacturing thepolymerised thermoset, which process comprises the steps of:

Preparing a polymerisable thermoset composition as described herein, and

Polymerising the polymerisable thermoset composition at temperatures ina range from 100 to 180° C.

The present embodiment further relates to the use of the polymerisablethermoset composition as described herein to manufacture lightweightconstruction components, preferably carbon fibre composites (CFRP).

The present embodiment also relates to a lightweight constructioncomponent, preferably carbon fibre composite (CFRP), containing thepolymerised thermoset as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the subject matter may be derived byreferring to the detailed description and claims when considered inconjunction with the following figures, wherein like reference numbersrefer to similar elements throughout the figures.

FIG. 1 shows a DMA spectrum of the compositionPT15/HP4710/HFC-X=(1/0.5)/0.07, which further contains 9.1% by weightAlbidur® EP 2240A.

FIG. 2 shows a DMA spectrum of the compositionPT15/HP4710/HFC-X=(1/0.5)/0.07, which further contains 13.8% by weightAlbidur® EP 5341.

FIG. 3 shows a DMA spectrum of the compositionPT15/HP4710/HFC-X=(1/0.5)/0.07, which further contains 9.1% by weightAlbidur® EP 5341.

FIG. 4 shows a DMA spectrum of the compositionPT15/HP4710/HFC-X=(1/0.5)/0.07, which further contains 9.1% by weightAlbidur® XP10669.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and isnot intended to limit the disclosed embodiments or the application anduses thereof. Furthermore, there is no intention to be bound by anytheory presented in the preceding background detailed description.

The embodiments disclosed herein relate to a polymerisable thermosetcomposition comprising: a) a di- or polyfunctional organic cyanate esterresin, b) a naphthalene based epoxy resin, and c1) at least onephosphorus-containing phenol and/or c2) at least onephosphorus-containing epoxy and at least one diamine.

The term “polymerisable” means that under suitable conditions, such aselevated temperature or with the aid of catalysts, the individualcomponents of the composition can be polymerised.

The term “thermoset” refers to a prepolymer that can no longer bereshaped after it has been polymerised and cured.

A requirement of the embodiment is that the polymerisable thermosetcomposition contains c1) at least one phosphorus-containing phenoland/or c2) at least one phosphorus-containing epoxy and at least onediamine.

The phosphorus-containing phenol is preferably a(hydrocarbyl-)-phosphonic acid ester and/or contains9-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as a structural unit.

More preferably, the phosphorus-containing phenol contains one of thefollowing structural units (I) and (II) wherein

-   -   n is a number between 1 and 1000, preferably between 200 and        500,    -   o is a number between 0 and 4, preferably between 0 and 2, more        preferably 0 or 1, and is most preferably 0,    -   p is a number between 0 and 4, preferably between 0 and 2, more        preferably 0 or 1, and is most preferably 0,    -   r is a number between 0 and 3, preferably between 0 and 2, more        preferably 0 or 1, and is most preferably 0,    -   R¹ is a C₁-C₁₀ alkyl,    -   R² is a C₁-C₁₀ alkyl, and    -   R³ is a C₁-C₁₀ alkyl

or wherein

-   -   s is a number between 1 and 1000, preferably between 100 and        600,    -   t is a number between 0 and 4, preferably between 0 and 2, more        preferably 0 or 1 and most preferably is 0, and    -   R⁴ is a C₁-C₁₀ alkyl.

In one embodiment, the polymerisable thermoset composition contains acompound containing structural unit (I), wherein n is a number between 1and 1000, o, p and r are each independently a number between 0 and 4,and R¹, R² and R³ are each independently a C₁-C₁₀ alkyl.

The polymerisable thermoset composition may for example contain acompound containing structural unit (I), wherein n is a number between200 and 500, o, p and r are each independently a number between 0 and 4,and R¹, R² and R³ are each independently a C₁-C₁₀ alkyl.

For the purposes of the present embodiment, the term “alkyl” refers to aradical from a saturated aliphatic group, including linear alkyl groupsand branched alkyl groups, wherein the linear alkyl groups and branchedalkyl groups are preferably not substituted.

The bond on the salicylate group of the structural unit according toformula (I) with the next monomer unit is preferably in the orthoposition to the OH group.

The polymerisable thermoset composition preferably contains a compoundcontaining structural unit (I) wherein n is a number between 1 and 1000,o, p and r are each independently a number between 0 and 4, and R¹, R²and R³ are each independently a C₁-C₁₀ alkyl, and the bond on thesalicylate group of the structural unit according to formula (I) withthe next monomer unit is in the ortho position to the OH group.

For example, the polymerisable thermoset composition contains a compoundcontaining structural unit (I) wherein n is a number between 200 and500, o, p and r are each independently a number between 0 and 4, and R¹,R² and R³ are each independently a C₁-C₁₀ alkyl, and the bond on thesalicylate group of the structural unit according to formula (I) withthe next monomer unit is in the ortho position to the OH group.

In one embodiment, the polymerisable thermoset composition contains acompound containing structural unit (I) wherein n is a number between 1and 1000, o, p and r are each 0 or 1, and R¹, R² and R³ are eachindependently a C₁-C₁₀ alkyl. For example, the polymerisable thermosetcomposition contains a compound containing structural unit (I) wherein nis a number between 1 and 1000, o, p and r are each 0 or 1, and R¹, R²and R³ are each independently a C₁-C₁₀ alkyl, and the bond on thesalicylate group of the structural unit according to formula (I) withthe next monomer unit is in the ortho position to the OH group.

In one embodiment, the polymerisable thermoset composition contains acompound containing structural unit (I) wherein n is a number between200 and 500, o, p and r are each 0 or 1, and R¹, R² and R³ are eachindependently a C₁-C₁₀ alkyl. For example, the polymerisable thermosetcomposition contains a compound containing structural unit (I) wherein nis a number between 200 and 500, o, p and r are each 0 or 1, and R¹, R²and R³ are each independently a C₁-C₁₀ alkyl, and the bond on thesalicylate group of the structural unit according to formula (I) withthe next monomer unit is in the ortho position to the OH group

For example, the polymerisable thermoset composition contains a compoundcontaining structural unit (I) wherein n is a number between 1 and 1000and o, p and r are each 0. For example, the polymerisable thermosetcomposition contains a compound containing structural unit (I) wherein nis a number between 1 and 1000 and o, p and r are each 0, and the bondon the salicylate group of the structural unit according to formula (I)with the next monomer unit is in the ortho position to the OH group.

For example, the polymerisable thermoset composition contains a compoundcontaining structural unit (I) wherein n is a number between 200 and 500and o, p and r are each 0. For example, the polymerisable thermosetcomposition contains a compound containing structural unit (I) wherein nis a number between 200 and 500 and o, p and r are each 0, and the bondon the salicylate group of the structural unit according to formula (I)with the next monomer unit is in the ortho position to the OH group.

For example, the polymerisable thermoset composition contains a compoundcontaining structural unit (II), wherein s is a number between 1 and1000, t is a number between 0 and 4 and R⁴ is a C₁-C₁₀ alkyl.

For example, the polymerisable thermoset composition contains a compoundcontaining structural unit (II), wherein s is a number between 100 and600, t is a number between 0 and 4 and R⁴ is a C₁-C₁₀ alkyl.

The polymerisable thermoset composition may for example contain acompound containing structural unit (II), wherein s is a number between1 and 1000, t is a number between 0 and 2 and R⁴ is a C₁-C₁₀ alkyl.

The polymerisable thermoset composition may for example contain acompound containing structural unit (II), wherein s is a number between100 and 600, t is a number between 0 and 2 and R⁴ is a C₁-C₁₀ alkyl.

The polymerisable thermoset composition may for example contain acompound containing structural unit (II), wherein s is a number between1 and 1000, t is a number between 0 and 1 and R⁴ is a C₁-C₁₀ alkyl.

The polymerisable thermoset composition may for example contain acompound containing structural unit (II), wherein s is a number between100 and 600, t is a number between 0 and 1 and R⁴ is a C₁-C₁₀ alkyl.

The polymerisable thermoset composition may for example contain acompound containing structural unit (II), wherein s is a number between1 and 1000 and t=zero.

The polymerisable thermoset composition may for example contain acompound containing structural unit (II), wherein s is a number between100 and 600 and t=zero.

The following compounds are examples of the phosphorus-containing phenol

wherein n is a number between 1 and 1000, preferably between 200 and 500or

wherein s is a number between 1 and 1000, preferably between 100 and600.

For example, the phosphorus-containing epoxy is a(hydrocarbyl-)-phosphonic acid ester and/or contains9-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as a structural unit.The phosphorus-containing epoxy preferably contains

9-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as the structural unit.

The phosphorus-containing epoxy preferably contains the followingstructural unit (III) wherein:

-   -   a is a number between 0 and 4, preferably between 0 and 2, more        preferably 0 or 1 and most preferably is 0    -   b is a number between 0 and 4, preferably between 0 and 2, more        preferably 0 or 1 and most preferably is 0,    -   c is a number between 0 and 3, preferably between 0 and 2, more        preferably 0 or 1 and most preferably is 0,    -   d is a number between 0 and 3, preferably between 0 and 2, more        preferably 0 or 1 and most preferably is 0,    -   e is a number between 1 and 1000, preferably between 200 and        500,    -   f is a number between 1 and 1000, preferably between 50 and 200,    -   R¹⁰ is a C₁-C₁₀ alkyl,    -   R¹¹ is a C₁-C₁₀ alkyl,    -   R¹² is a C₁-C₁₀ alkyl or hydrogen, preferably methyl or        hydrogen, and most preferably hydrogen,    -   R¹³ is a C₁-C₁₀ alkyl or hydrogen, preferably methyl or        hydrogen, and most preferably hydrogen,    -   R¹⁴ is a C₁-C₁₀ alkyl or hydrogen, preferably methyl or        hydrogen, and most preferably hydrogen,    -   R¹⁵ is a C₁-C₁₀ alkyl or hydrogen, preferably methyl or        hydrogen, and most preferably hydrogen,    -   R¹⁶ is a C₁-C₁₀ alkyl,    -   R¹⁷ is a C₁-C₁₀ alkyl,    -   R¹⁸ is a C₁-C₁₀ alkyl or hydrogen, preferably methyl or        hydrogen, and most preferably hydrogen, and    -   R¹⁹ is a C₁-C₁₀ alkyl or hydrogen, preferably methyl or        hydrogen, and most preferably hydrogen.

The methylene groups in structural unit (III) are preferably eachlocated at the ortho position to the oxygen atom.

In one embodiment, in structural unit (III)

-   -   a is either 0 or 1, preferably 0,    -   b is either 0 or 1, preferably 0,    -   c is either 0 or 1, preferably 0,    -   d is either 0 or 1, preferably 0,    -   e is a number between 1 and 1000, preferably between 200 and        500,    -   f is a number between 1 and 1000, preferably between 50 and 200,    -   R¹⁰ is a C₁-C₁₀ alkyl,    -   R¹¹ is a C₁-C₁₀ alkyl,    -   R¹² is methyl or hydrogen, preferably hydrogen,    -   R¹³ is methyl or hydrogen, preferably hydrogen,    -   R¹⁴ is methyl or hydrogen, preferably hydrogen,    -   R¹⁵ is methyl or hydrogen, preferably hydrogen,    -   R¹⁶ is a C₁-C₁₀ alkyl,    -   R¹⁷ is a C₁-C₁₀ alkyl,    -   R¹⁸ is methyl or hydrogen, preferably hydrogen,    -   R¹⁹ is methyl or hydrogen, preferably hydrogen.

For example, in structural unit (III)

-   -   a is either 0 or 1, preferably 0,    -   b is either 0 or 1, preferably 0,    -   c is either 0 or 1, preferably 0,    -   d is either 0 or 1, preferably 0,    -   e is a number between 1 and 1000, preferably between 200 and        500,    -   f is a number between 1 and 1000, preferably between 50 and 200,    -   R¹⁰ is a C₁-C₁₀ alkyl,    -   R¹¹ is a C₁-C₁₀ alkyl,    -   R¹² is methyl or hydrogen, preferably hydrogen,    -   R¹³ is methyl or hydrogen, preferably hydrogen,    -   R¹⁴ is methyl or hydrogen, preferably hydrogen,    -   R¹⁵ is methyl or hydrogen, preferably hydrogen,    -   R¹⁶ is a C₁-C₁₀ alkyl,    -   R¹⁷ is a C₁-C₁₀ alkyl,    -   R¹⁸ is methyl or hydrogen, preferably hydrogen,    -   R¹⁹ is methyl or hydrogen, preferably hydrogen

The methylene groups in structural unit (III) are each located at theortho position to the oxygen atom.

For example, in structural unit (III) a, b, c and e are each 0, e is anumber between 1 and 1000, f is a number between 1 and 1000 and R¹²,R¹³, R¹⁴, R¹⁵, R¹⁸ and R¹⁹ are each hydrogen. For example in structuralunit (III), a, b, c and e are each 0, e is a number between 1 and 1000,f is a number between 1 and 1000, and R¹², R¹³, R¹⁴, R¹⁵, R¹⁸ and R¹⁹are each hydrogen, and the methylene groups are each located on theortho position to the oxygen atom.

For example, in structural unit (III) a, b, c and e are each 0, e is anumber between 200 and 500, f is a number between 50 and 200 and R¹²,R¹³, R¹⁴, R¹⁵, R¹⁸ and R¹⁹ are each hydrogen. For example, in structuralunit (III) a, b, c and e are each 0, e is a number between 200 and 500,f is a number between 50 and 200 and R¹², R¹³, R¹⁴, R¹⁵, R¹⁸ and R¹⁹ areeach hydrogen, and the methylene groups are each located on the orthoposition to the oxygen atom.

The following compound is an example of the phosphorus-containing epoxy:

wherein e is a number between 1 and 1000, preferably between 50 and 200,and

wherein f is a number between 1 and 1000, preferably between 50 and 200,

and the methylene groups are each located on the ortho position to theoxygen atom.

Such an epoxy represents an additional epoxy in the resin mixture, andfor this reason a diamine is also used as a curing agent.

The diamine is typically an aromatic diamine, preferably selected fromthe group comprising 2,4-diaminotoluene, 2,6-diaminotoluene,3,5-diethyl-2,4-diaminotoluene, 3,5-diethyl-2,6-diaminotoluene, andprimary mono-, di-, tri- or tetra-alkyl substituted 4,4′-diaminodiphenylmethanes, 6-methyl-2,4-bis(methylthio)phenylene-1,3-diamine and2-methyl-4,6-bis(methylthio)phenylene-1,3-diamine.

If the polymerisable thermoset composition according to the embodimentshould contain diamine, the total quantity of diamine relative to thepolymerisable thermoset composition is 0.25 to 5.0% by weight,preferably 0.1 to 2.0% by weight or 0.2 to 1.5% by weight.Alternatively, the polymerisable thermoset composition contains thearomatic diamine, preferably in a quantity of for example 0.4 to 1.2% byweight or 0.5 to 1.0% by weight.

In one embodiment, component c2) is present and component c1) is notpresent.

In a further, preferred embodiment, component c1) is present andcomponent c2) is not present. In this embodiment, a diamine is normallynot needed to function as an additional curing component. Thepolymerisable thermoset composition of this embodiment preferably doesnot contain a diamine.

The total quantity of components c1) and c2) relative to thepolymerisable thermoset composition is typically in the range from 5.5to 20% by weight, preferably in the range from 6.0 to 15% by weight, andmore preferably in the range from 6.5 to 12% by weight.

Since components c1) and/or c2) function as curing agents, curing agentsand/or catalysts with harmful health effects do not need to be used.

The polymerisable thermoset composition according to the embodimentpreferably does not contain any curing agents and/or catalysts withharmful health effects.

A further requirement of the present embodiment is that thepolymerisable thermoset composition comprises a di- or polyfunctionalorganic cyanate ester resin.

The choice of di- or polyfunctional organic cyanate ester resin is notcritical. In theory, any at least difunctional cyanate ester resin canbe used. However, it is preferable if di- or polyfunctional organiccyanate ester resins having formula (IV) are used:

wherein R¹, R² and R³ are each independently hydrogen or C₁-C₁₀ alkyl,and n represents an integer from 0 to 20.

In one embodiment of the present embodiment, the di- or polyfunctionalorganic cyanate ester resin is a cyanate having formula (IV), whereinR¹, R² and R³ are independently hydrogen or C₁-C₁₀ alkyl and nrepresents an integer from 0 to 10. The di- or polyfunctional organiccyanate ester resin is preferably a cyanate having formula (IV), whereinR¹, R² and R³ are independently hydrogen or C₁-C₁₀ alkyl, and nrepresents an integer from 1 to 5.

The methylene group in formula (IV) may be at the ortho position to thecyanate group in each case. The methylene group in formula (IV) ispreferably located in the ortho position to the cyanate group in eachcase.

For example, the di- or polyfunctional organic cyanate ester resin is acyanate having formula (IV), wherein R¹, R² and R³ are hydrogen orC₁-C₁₀ alkyl, and n represents an integer from 0 to 20. Alternatively,the di- or polyfunctional organic cyanate ester resin is a cyanatehaving formula (IV), wherein R¹, R² and R³ are hydrogen or C₁-C₁₀ alkyl,and n represents an integer from 0 to 10. The di- or polyfunctionalorganic cyanate ester resin is preferably a cyanate having formula (IV),wherein R¹, R² and R³ are hydrogen or C₁-C₁₀ alkyl, and n represents aninteger from 1 to 5. The di- or polyfunctional organic cyanate esterresin is for example a cyanate having formula (IV), wherein R¹, R² andR³ are hydrogen or C₁-C₁₀ alkyl, and n represents an integer from 1 to5, and the methylene group is in the ortho position to the cyanate groupin each case.

In one embodiment of the present embodiment, the di- or polyfunctionalorganic cyanate ester resin is a cyanate having formula (IV);

wherein R¹, R² and R³ are hydrogen and n represents an integer from 0 to20.

For example, the di- or polyfunctional organic cyanate ester resin is acyanate having formula (IV), wherein R¹, R² and R³ are hydrogen and nrepresents an integer from 1 to 10. The di- or polyfunctional organiccyanate ester resin is preferably a cyanate having formula (IV), whereinR¹, R² and R³ are hydrogen and n represents an integer from 1 to 5.

In one embodiment of the present embodiment, the di- or polyfunctionalorganic cyanate ester resin is a cyanate having formula (IV), whereinR¹, R² and R³ are hydrogen and n represents 1, 2 or 3. For example, thedi- or polyfunctional organic cyanate ester resin is a cyanate havingformula (IV), wherein R¹, R² and R³ are hydrogen and n represents 1, 2or 3, and the methylene is located in the ortho position to the cyanategroup in each case.

The cited di- or polyfunctional organic cyanate ester resins havingformula (I) may also be used as monomers or as prepolymers, alone or inmixtures with each other.

The polymerisable thermoset composition preferably comprises the di- orpolyfunctional organic cyanate ester resin in a quantity from forexample 50 to 80% by weight, or 55 to 75% by weight, relative to thetotal weight of the composition. Alternatively, the polymerisablethermoset composition comprises the di- or polyfunctional organiccyanate ester resin preferably in in a quantity from for example 55 to70% by weight, or 60 to 65% by weight relative to the total weight ofthe composition.

A further requirement of the present embodiment is that thepolymerisable thermoset composition comprises a naphthalene-based epoxyresin.

In theory, any naphthalene-based epoxy resin can be used. Preferably,however, naphthalene-based epoxy resins that have four glycidyl etherfunctionalities per repeating unit are used. This high number ofglycidyl ether functionalities is particularly favourable for obtaininga thermoset with high crosslinking density.

In one embodiment of the present embodiment, the naphthalene-based epoxyresin is a polymeric naphthalene-based epoxy resin.

For example, the naphthalene-based epoxy resin is a naphthalene-basedepoxy resin having formula (V):

wherein n represents an integer from 1 to 50.

The naphthalene-based epoxy resin is preferably a naphthalene-basedepoxy resin having formula (V), wherein n represents an integer from 1to 40 or 1 to 20. Alternatively, the naphthalene-based epoxy resin is anaphthalene-based epoxy resin having formula (V), wherein n representsan integer from 1 to 10 or 1 to 5.

The cited naphthalene-based epoxy resins having formula (V) may also beused as monomers or as prepolymers, alone or in mixtures with eachother.

The polymerisable thermoset composition comprises the naphthalene-basedepoxy resin preferably in a quantity of for example 19.9 to 48% byweight, or 24.8 to 43.5% by weight relative to the total weight of thecomposition. Alternatively, the polymerisable thermoset compositioncomprises the naphthalene-based epoxy resin preferably in a quantity offor example 29.6 to 43.8% by weight or 29.6 to 35% by weight, relativeto the total weight of the composition.

To obtain a polymerised thermoset with high thermal stability, it isadvantageous if the polymerisable thermoset composition contains the di-or polyfunctional organic cyanate ester resin and the naphthalene-basedepoxy resin in a certain weight ratio.

Therefore, the polymerisable thermoset composition preferably containsthe di- or polyfunctional organic cyanate ester resin and thenaphthalene-based epoxy resin in a weight ratio (weight/weight) from10:1 to 1:1. For example, the polymerisable thermoset compositioncontains the di- or polyfunctional organic cyanate ester resin and thenaphthalene-based epoxy resin in a weight ratio (weight/weight) from 7:1to 1:1 or from 5:1 to 1:1. In one embodiment of the present embodiment,the polymerisable thermoset composition contains the di- orpolyfunctional organic cyanate ester resin and the naphthalene-basedepoxy resin in a weight ratio (weight/weight) of about 2:1.

In one embodiment of the present embodiment, the naphthalene-based epoxyresin has an EEW from 100 to 500 g/eq, preferably from 125 to 300 g/eqand most particularly preferably from 150 to 200 g/eq.

In order to obtain a polymerised thermoset with high impact resistance,it is advantageous if the polymerisable thermoset composition comprisesat least one high-performance thermoplast, also called an impactmodifier.

For the purposes of the present embodiment, a “high-performancethermoplast” is a thermoplast with which the impact resistance of thepolymerised thermosets may be modified, preferably increased.

In one embodiment of the present embodiment, the polymerisable thermosetcomposition therefore comprises a) a di- or polyfunctional organiccyanate ester resin, b) a naphthalene based epoxy resin, and c1) atleast one phosphorus-containing phenol, and/or c2) at least onephosphorus-containing epoxy and at least one diamine, and additionally,d) at least one high-performance thermoplast.

For example, the polymerisable thermoset composition comprises at leastone high-performance thermoplast, also called an impact modifier,selected from the group comprising polysulfones (PSU), for examplepolyethersulfone (PES) and polyphenylsulfone (PPSU), polyetherimide(PEI), polysulfone (PSU), polycarbonate (PC), silicone rubber andmixtures thereof.

The impact modifier may also be present in the form of core-shellparticles, in the present case preferably containing at least onehigh-performance thermoplast, as described above, typically as the core.

The polymerisable thermoset composition comprises for example siliconerubber as the high-performance thermoplast, preferably in the form ofcore-shell particles.

The shell of the core-shell particles typically consists of a polymermatrix containing an epoxy resin, a cyanate ester or mixtures thereof.The core contains, preferably consists of, a different polymer, selectedfor example from the group comprising silicone rubber, nitrile rubber,styrene-butadiene rubber, polyisoprene rubber, polybutadiene, butylrubber, fluoroelastomers, etc., and mixtures thereof, for examplesilicone rubber.

For example, the core contains, preferably consists of, silicone rubber,and the shell contains, preferably consists of, an epoxy resin.Alternatively, the core contains, preferably consists of, siliconerubber, and the shell contains, preferably consists of, a cyanate ester.

In the case of an epoxy resin, the EEW (epoxy equivalent weight) thereofis typically between 200 and 350 g/eq.

The weight ratio between the core and shell of the core-shell particlesmay be for example 25:75 to 75:25, preferably 30:70 to 60:40, morepreferably 35:65 to 50:50.

Examples of suitable core-shell particles are Albidur® EP 5341, Albidur®EP 2240A and Albidur® XP 10669. More details about the properties anduse of these additives are provided in “Fibre-reinforced compositesbased on epoxy resins modified with elastomers and surface-modifiedsilica nanoparticles”, Journal of Material Science 2013 (StephanSprenger).

The polymerisable thermoset composition comprises the at least onehigh-performance thermoplast preferably in a quantity from for example0.1 to 20% by weight, or 0.5 to 15% by weight relative to the totalweight of the composition. Alternatively, polymerisable thermosetcomposition comprises the at least one high-performance thermoplastpreferably in a quantity from for example 1.0 to 18% by weight or 2.0 to14% by weight relative to the total weight of the composition.

In the case of core-shell particles, the weight specification refers tothe total mass of the core-shell particle.

In order to obtain a polymerised thermoset with high impact resistance,it is advantageous if the polymerisable thermoset composition containsthe mixture of di- or polyfunctional organic cyanate ester resin andnaphthalene-based epoxy resin and the at least one high-performancethermoplast in a certain weight ratio.

For example, the polymerisable thermoset composition contains themixture of di- or polyfunctional organic cyanate ester resin andnaphthalene-based epoxy resin and the at least one high-performancethermoplast in a weight ratio (weight/weight) from 100:1 to 3:1. In oneembodiment of the present embodiment, the polymerisable thermosetcomposition contains the mixture of di- or polyfunctional organiccyanate ester resin and naphthalene-based epoxy resin and the at leastone high-performance thermoplast in a weight ratio (weight/weight) from50:1 to 3:1 or from 40:1 to 5:1. The polymerisable thermoset compositionpreferably contains the mixture of di- or polyfunctional organic cyanateester resin and naphthalene-based epoxy resin and the at least onehigh-performance thermoplast in a weight ratio (weight/weight) from 33:1to 10:1.

Still more auxiliary agents and additives may be added to thepolymerisable thermoset composition. For example, lubricants such asfatty acid esters, metal soaps thereof, fatty acid amides and siliconecompounds, antiblocking agents, inhibitors, stabilisers againsthydrolysis, light, heat and discolouration, flame protection agents,dyes, pigments, inorganic or organic filler materials to enhancemechanical and/or dielectric properties and reinforcing agents may beadded to the polymerisable thermoset composition. For example, fibrousreinforcing agents such as inorganic fibres that are manufacturedaccording to the state of the art may be added as reinforcing agents.The polymerisable thermoset composition may contain carbon fibres, forexample.

Based on the advantages offered by the polymerisable thermosetcomposition, the present embodiment also relates to a polymerisedthermoset that represents a reaction product of the polymerisablethermoset composition as described herein.

The polymerised thermoset offers the advantage that it has good thermalresistance. In particular, the polymerised thermoset has improvedthermal resistance compared with pure epoxy resins. Furthermore, thepolymerised thermoset has a high glass transition temperature. Inparticular, the polymerised thermoset has a higher glass transitiontemperature than previously known CE/epoxy combinations.

The polymerised thermoset according to the embodiment typically has aglass transition temperature from 285° C. to 300° C.

In addition or alternatively thereto, the polymerised thermosetaccording to the embodiment has a curing temperature in a range from 100to 180° C. The polymerised thermoset according to the embodimentpreferably has a curing temperature in a range from 125 to 175° C.

In one embodiment of the present embodiment, the polymerised thermosetaccording to the embodiment has a density in a range from 1.20 to 1.35g/cm³ and preferably in a range from 1.25 to 1.30 g/cm³.

In addition or alternatively thereto, the polymerised thermosetaccording to the embodiment has a water absorption capacity in a rangefrom 1.2 to 1.35% by weight, based on the total weight of thepolymerised thermoset.

In one embodiment of the present embodiment, the polymerised thermosetaccording to the embodiment has a decomposition temperature in a rangefrom 350 to 400° C. and preferably in a range from 360 to 380° C.

A vertically suspended sample of the polymerised thermoset according tothe embodiment that has been set alight preferably goes out within notmore than 30 seconds, and release no burning droplets of molten plastic,as determined in the to the “Vertical Burn Test” according to DIN EN60695-11-10.

A further aspect of the present embodiment relates to a process formanufacturing a polymerised thermoset, as described herein. The processcomprises the steps of: providing a polymerisable thermoset compositionas described herein, and polymerising the polymerisable thermosetcomposition at temperatures in a range from 100 to 180° C.

The polymerisable thermoset composition according to the embodiment maygenerally be provided by mixing the di- or polyfunctional organiccyanate ester resin, the naphthalene-based epoxy resin, the at least onephosphorus-containing phenol and/or the at least onephosphorus-containing epoxy and at least one diamine and optionaladditives, such as the at least one high-performance thermoplast. In oneembodiment of the present embodiment, the polymerisable thermosetcomposition according to the embodiment is poured into a preferred mouldor hollow space and is then polymerised in situ. Polymerisation takesplace at temperatures in a range from 100 to 180° C. or from 125 to 175°C., for example at approximately 150° C., preferably for a total of 1 to10 hours or for 2 to 5 hours. Polymerisation may be carried out in asingle, continuous process or in multiple different and chronologicallyseparate steps. Polymerisation is preferably carried out in a single,continuous process.

In one embodiment of the present embodiment, the process formanufacturing a polymerised thermoset comprises a post-curing step iii),in which the polymerised thermoset is post-cured. Post-curing takesplace at temperatures in a range from 200 to 280° C. or from 200 to 250°C., for example at about 220° C., preferably for a total of 1 to 10hours or for 2 to 5 hours. Post-curing may be carried out in a single,continuous process or in multiple different and chronologically separatesteps. Post-curing is preferably carried out in a single, continuousprocess.

In view of the advantages offered by the polymerised thermoset accordingto the embodiment, the present embodiment also relates to the use of thepolymerisable thermoset composition as described herein to manufacturelightweight construction components, preferably carbon fibre composites(CFRP). For example, the polymerised thermoset is used as a lightweightconstruction component in load-bearing lightweight construction elementsthat are exposed to thermal stresses, and are particularly exposed toelevated temperatures, for example temperatures higher than 200° C. Inparticular, the polymerised thermoset is used as a lightweightconstruction component in aerospace applications. For example, thepolymerised thermoset is used as a lightweight construction component onsatellites, rockets, aircraft such as passenger aeroplanes orhelicopters, in rail vehicles such as trains, water vehicles such aspassenger ships, or road vehicles such as cars.

A further aspect of the present embodiment therefore relates to alightweight construction component, preferably carbon fibre composite(CFRP), which contains the polymerised thermoset as described herein.

As was explained earlier, polymerised thermosets may be obtained on thebasis of the polymerisable thermoset composition according to theembodiment, which products are resistant to high temperatures and have ahigh glass transition temperature and good impact resistance. Thepolymerisable thermoset composition according to the embodiment may alsobe cured at moderate temperatures, and at the same time has improvedresistance to hydrolysis. The polymerisable thermoset compositionaccording to the embodiment also contains no curing agents and/orcatalysts that are hazardous to health.

Examples

Methods

a.) DSC measurements were taken with the aid of the “DSC Q2000” devicemade by TA Instruments. The spectra were recorded using the “ThermalAdvantage Release 5.4.0” software and analysed using the “UniversalAnalysis 2000, Version 4.5A” software produced by TA Instruments. Theheating rate was 5 K/min at a temperature from 20° C. to 350° C.

b.) TGA measurements were taken with the aid of the “TGA Q5000” devicemade by TA Instruments. The spectra were recorded using the “ThermalAdvantage Release 5.4.0” software and analysed using the “UniversalAnalysis 2000, Version 4.5A” software produced by TA Instruments. Theheating rate was 10 K/min, at a temperature from 20° C. to 1000° C. Eachmeasurement was carried out both in an inert gas atmosphere (N2) and inan oxygen atmosphere (ambient air).

c.) DMA and rheology measurements Viscosity measurements anddetermination of glass transition temperatures (Tg) of the materialswere carried out using the “Advanced Rheometric Expansion System (ARES)”rheometer manufactured by Rheometric Scientific. For analysis, thesoftware “Rheometric Scientific, Version V6.5.8” was used. The heatingrates were 3 K/min in all cases. Glass transition corresponds to themaximum of the tan(6) function.

d.) UL-94 flammability test. The flammability properties of thematerials were determined in accordance with DIN EN 60695-11-10, usingthe “Vertical Burn Test”. The flame treatment time lasted for up to 60sec.

2. Materials Used:

Primaset® PT15 (available from Lonza) is anoligo(3-methylene-1,5-phenylcyanate).

Epiclon® HP-4710 (available from DIC Corporation) is anoligo(1,1′,5,5′-bis-(2,7-diglycidyloxy-1-naphthyl) methane) with an EEWof 170 g/eq.

Epiclon® HFC-X (available from DIC Corporation) is an organophosphorousphenolic resin with an OH equivalent weight of 428 g/eq and a phosphoruscontent of 10.4% by weight.

XP3775 (available from Schill+Seilacher “Struktol” GmbH) is aDOPO-modified Novolak with a phosphor content of 7.5% by weight and aEEW <2000 g/eq.

Fyrol® PMP (available from ICL) is a poly(m-phenylmethylphosphonate)with a phosphor content of 17.5%.

Core-Shell Particles:

Albidur® EP 5341 is a dispersion of an elastomer with high-performancecapabilities in a cycloaliphatic epoxy resin with a silicone rubbercontent of 40% by weight and a EEW von 225-255 g/eq.

Albidur® EP 2240A is a dispersion of an elastomer with high-performancecapabilities in an epoxy resin based on bisphenol A with a siliconerubber content of 40% by weight and a EEW von 290-315 g/eq.

Albidur® XP10669 s a dispersion of an elastomer with high-performancecapabilities in a cyanate ester consisting of 4,4′-ethylidenediphenyldicyanate. The silicone rubber content is 40% by weight and thecontent of 4,4′-ethylidene diphenyldicyanate is 60% by weight.

Presentation of the Materials:

The resins Primaset PT15, Epiclon HP 47110, the correspondingorganophosphorous modifier and the corresponding impact modifier areweighed in together and then melted in a convection oven and homogenisedwith a dispersing agent at 80° C. Then, the mixture is first degassed inthe vacuum oven for 2 hours at 80° C. and then degassed for 1 hour at110° C. The hot thermoset mixture is then poured into an aluminiumcasting mould that has been preheated to 130° C., and undergoes thefollowing heating cycle:

1.) 130° C.→160° C. (ramp=2K/min)

2.) Maintain at constant temp. 160° C. for 4 hours

3.) 160° C.→30° C. (ramp=3K/min)

4.) free-standing post-curing: 230° C. for 4 hours

The results from the DSC tests show that the cured thermoset has a glasstransition temperature from 285° C. to 300° C.

The characterisation of the flame retardant properties and of the DMAtests is described in the following.

For this purpose, blends of the composition PT15/HP4710/FSM wereprepared. The mixture ratio of PT15/HP4710 was 1/0.5.

Flame Wt. proportion UL-94 retardant FSM/wt % evaluation¹⁾ T_(g)/° C.T_(onset)/° C. HFC-X 2.9 Burns 294 269 HFC-X 4.8 Burns 291 264 HFC-X 9.1V-0²⁾ 281 249 Fyrol ® PMP 2.9 Burns 306 281 Fyrol ® PMP 4.8 Burns 288260 Fyrol ® PMP 6.5 V-1³⁾ 293 267 Fyrol ® PMP 9.1 V-1   283 254 ¹⁾Theflame treatment time did not exceed 60 s. All test samples could not beflamed for at least 12 sec, so all received the evaluation V-0 for t <12 s. ²⁾V-0 A vertically suspended test sample that was alight went outwithin 10 sec without releasing burning droplets of melted plastic.³⁾V-1: A vertically suspended test sample that was alight went outwithin 30 sec without releasing burning droplets of melted plastic.

1.) The flame treatment time did not exceed 60 s. All test samples couldnot be flamed for at least 12 sec, so all received the evaluation V-0for t<12 s.

2.) V-0 A vertically suspended test sample that was alight went outwithin 10 sec without releasing burning droplets of melted plastic.

3.) V-1: A vertically suspended test sample that was alight went outwithin 30 sec without releasing burning droplets of melted plastic.

The impact resistance modifications using core-shell particles aredescribed below. For this, PT15/HP4710/HFC-X/Modifier blends were used.The composition of (PT15/HP4710)/HFC-X was in the ratio of:(1/0.5)/0.07. The quantity of impact modifier is listed in the followingtable.

Wt. proportion Modifier Modifier/wt % Tg/° C. Tonset/° C. AlbidurEP2240A 9.1 285 258 Albidur EP5340A 9.1 289 264 Albidur EP5340A 13.8 284257 Albidur XP10669 9.1 291 265

What is claimed is:
 1. A polymerisable thermoset composition,comprising: a) a di- or polyfunctional organic cyanate ester resin; b) anaphthalene based epoxy resin; and c1) at least onephosphorus-containing phenol; and/or c2) at least onephosphorus-containing epoxy and at least one diamine; wherein thepolymerisable thermoset composition comprises at least onehigh-performance thermoplast.
 2. The polymerisable thermoset compositionaccording to claim 1, wherein the phosphorus-containing phenol is a(hydrocarbyl-)phosphonic acid ester and/or contains9-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as the structural unit.3. The polymerisable thermoset composition according to claim 1, whereinthe phosphorus-containing epoxy is a (hydrocarbyl-)phosphonic acid esterand/or contains 9-dihydroz-9-oxa-10-phosphaphenanthrene-10-oxide as thestructural unit.
 4. The polymerisable thermoset composition according toclaim 1, wherein the phosphorus-containing phenol contains one of thefollowing structural units:

wherein: n is a number between 1 and 1000, o is a number between 0 and4, p is a number between 0 and 4, r is a number between 0 and 3, R¹ is aC₁-C₁₀ alkyl, R² is a C₁-C₁₀ alkyl, and R³ is a C₁-C₁₀ alkyl; or

wherein: s is a number between 1 and 1000, t is a number between 0 and4, and R⁴ is a C₁-C₁₀ alkyl.
 5. The polymerisable thermoset compositionaccording to claim 1, wherein the phosphorus-containing epoxy containsthe following structural unit (III):

wherein a is a number between 0 and 4, b is a number between 0 and 4, cis a number between 0 and 3, d is a number between 0 and 3, e is anumber between 1 and 1000, f is a number between 1 and 1000, R¹⁰ is aC₁-C₁₀ alkyl, R¹¹ is a C₁-C₁₀ alkyl, R¹² is a C₁-C₁₀ alkyl or hydrogen,R¹³ is a C₁-C₁₀ alkyl or hydrogen, R¹⁴ is a C₁-C₁₀ alkyl or hydrogen,R¹⁵ is a C₁-C₁₀ alkyl or hydrogen, R¹⁶ is a C₁-C₁₀ alkyl, R¹⁷ is aC₁-C₁₀ alkyl, R¹⁸ is a C₁-C₁₀ alkyl or hydrogen, and R¹⁹ is a C₁-C₁₀alkyl or hydrogen.
 6. The polymerisable thermoset composition accordingto claim 1, wherein the di- or polyfunctional organic cyanate esterresin is a cyanate having formula (IV):

wherein R¹, R² and R³ are each independently hydrogen or C₁-C₁₀ alkyl,and n represents an integer from 0 to
 20. 7. The polymerisable thermosetcomposition according to claim 1, wherein the naphthalene-based epoxyresin represents a polymeric naphthalene-based epoxy resin.
 8. Thepolymerisable thermoset composition according to claim 1, wherein the atleast one high-performance thermoplast is selected from the groupcomprising polysulfones (PSU), polyetherimide (PEI), polysulfone (PSU),polycarbonate (PC), silicone rubber and mixtures thereof.
 9. Thepolymerisable thermoset composition according to claim 1, wherein thehigh-performance thermoplast is present in the form of core-shellparticles.
 10. The polymerisable thermoset composition according toclaim 9, wherein the shell of the core-shell particles contains an epoxyresin, a cyanate ester or mixtures thereof, and the core contains asilicone rubber.
 11. A polymerised thermoset constituting a reactionproduct of the polymerisable thermoset composition according to claim 1.12. A polymerised thermoset according to claim 11, wherein the thermosethas a glass transition temperature from 285° C. to 300° C. and/or curingtemperature in a range from 100 to 180° C.
 13. A process formanufacturing a polymerised thermoset, comprising the steps of: i)providing a polymerisable thermoset composition according to claim 1;ii) polymerising the polymerisable thermoset composition at temperaturesof from 100 to 180° C.
 14. Use of the polymerisable thermosetcomposition according to claim 1 to manufacture lightweight constructioncomponents.
 15. A lightweight construction component containing thepolymerised thermoset according to claim 11.